Dependency based boot sequence

It is possible to converting Debian to order the boot sequence using the LSB headers in the init.d scripts. This will get rid of several bugs in the current boot sequence, and make it easier to keep the sequence correct.

A new [:LSBInitScripts/DependencyBasedBoot/200805-status:status update message] is being worked on.

Advantages

Did you every need to insert a init.d scripts Y before init.d scripts Z and after init.d script X, where both Z and X is started using boot sequence number 20 (as in 20X and 20Z)? Adding your script as 20Y would not cut it, because you need Z to start before X. To do this, in Debian you currently need to talk to the maintainer of packages with scripts Z and X, asking one of them (or both) to move their script into a different number. Dependency based boot sequencing make it possible for each package maintainer to specify the dependencies of its scripts, and leave the number allocation to the dependency resolver.

Known issues

It is not possible to migrate between exim and postfix without purging the other package, due to conflicting provides.

Some scripts provide the same service, and this confuses insserv. Some of the scripts are scripts that have been removed from their package, but not properly removed from disk. This make insserv refuse to install these init.d scripts and thus the package fail to install when dependency based boot sequencing is enabled.

[http://bugs.debian.org/458582 A bug in insserv] make it report a dependency loop when there really isn't one. It happen when the combined dependency tree for both the start and stop sequence have a loop, but none of them have it individually.

Some init.d scripts have buggy headers, making them fail to install properly in the boot sequence.